Blow Molding

Many of Ticona’s resins are capable of being processed via blow molding, and are used in such applications as: small fuel tanks for lawn care tools, fuel floats, chemically resistant containers, HVAC or coolant ducts, multilayer structures, and pharmaceutical containers.  

There are 4 basic types of blow molding:

Continuous Parison Extrusion:
In this process an extruder produces a parison continuously. Two alternating molds or a number of molds in a rotary table (carousel) capture a length of parison where it is then blown into a part.

Intermittent Parison Extrusion
An extruder continuously produces molten plastic, which fills an accumulator.  A piston is used to push the plastic through a die into a parison shape.  This parison is then captured by a mold where it is blown into a part.

Injection Blow Molding:
A two-step process in which a preform is molded and kept in a near-molten condition.  It is then indexed into another mold and blown into a finished part.

Stretch and Blow Processing:
An amorphous preform is molded and then heated to a temperature above its glass transition temperature.  The preform is stretched (elongated) by a push rod and then blown into a container (bottles for soft drinks are produced from PET using this process).

Parison programming can also be used to vary the wall thickness over the length of the part or to maintain a uniform wall thickness for a complex part with areas of high blow up ratio.

Material Requirements

• Good melt strength (high zero shear rate viscosity & low melt index)
• Good melt stability (retention of molecular weight at processing temperatures)
• Reasonable “blow ratio” capabilities
• Good weldline strength

Most resins can be accommodated using injection blow molding, whereas the stretch blow molding process demands a high viscosity at the processing temperatures.

Ticona ‘Blowmoldable’ Products:

• Celcon® POM (M15HP, M25, GC25A, M or TX grades)
• Celanex® PBT (1600A, 1700A, 2002)
• Vandar® PBT (2100, 2500, 4602ZHR)
• Fortron® PPS (SKX-343, SKX-382, 1115LO)
• Vectran® LCP (V300P, V400P, V100P L950SX)
• Topas® COC (6013D-61, 6015D-61, 8007D-61)